508 Light Intensity Effect on Shrinkage Force of Light-Cured Composite Resin

2013 ◽  
Vol 2013.88 (0) ◽  
pp. _5-8_
Author(s):  
Mariko Nishimura ◽  
Sangjae Yoon ◽  
Kazuo Arakawa
Keyword(s):  
Light Intensity ◽  
Composite Resin ◽  
Intensity Effect ◽  
Shrinkage Force

scholarly journals Effect of light intensity and irradiation time on the polymerization process of a dental composite resin

2004 ◽  
Vol 7 (2) ◽  
pp. 313-318 ◽  
Author(s):  
José Augusto César Discacciati ◽  
Alisson Discacciati Neves ◽  
Rodrigo Lambert Oréfice ◽  
Flávio Juliano Garcia Santos Pimenta ◽  
Herbert Haueisen Sander
Keyword(s):  
Light Intensity ◽  
Composite Resin ◽  
Irradiation Time ◽  
Dental Composite ◽  
Polymerization Process ◽  
Dental Composite Resin ◽  
Effect Of Light

The Effects of Temperature and Light Intensity on the Polymerization Shrinkage of Light-cured Composite Filling Materials

2006 ◽  
Vol 7 (3) ◽  
pp. 12-21 ◽  
Author(s):  
Ahmed A. Elhejazi
Keyword(s):  
Light Intensity ◽  
Room Temperature ◽  
Environmental Temperature ◽  
Composite Resin ◽  
Comparable Amount ◽  
Polymerization Shrinkage ◽  
Filling Materials ◽  
Lower Light ◽  
Effects Of Temperature ◽  
Effect Of Light

Abstract The aim of this study was to investigate the effect of light intensity on polymerization shrinkage of resin composites. The five materials tested were Lite-Fil (A) (LFA), Lite-Fil (P) (LFP), Z100, Palfique, (PAL) and Tetric (TRC). Two types of measurements were made to determine the effects of environmental temperature and light intensity. Results were analyzed by two-way analysis of variance (ANOVA) and Newman-Keuls procedure at (P<0.05). The changes in temperature and/or light intensity strongly affected composite shrinkage. The amount of shrinkage for LFP at 100% light intensity in room temperature (23°C) was 1.26% and increased up to 2.29% at 60°C. By raising the temperature to 37°C and dropping the light intensity to 42% (459mW/cm2), the amount of polymerization shrinkage was similar to that with full light intensity, and statistically there were no significant differences between 37°C, 45°C, and 60°C. Lower temperatures and lower light intensities produce lower values of shrinkage. However, if the light intensity is below 28%, higher temperatures (60°C) must be applied to obtain a comparable amount of shrinkage. Clinical Relevance Pre-heating composite resin materials at body temperature (37°C) is likely to improve physical properties and compensate any drop of light intensity. Citation Elhejazi AA. The Effects of Temperature and Light Intensity on the Polymerization Shrinkage of Light-cured Composite Filling Materials. J Contemp Dent Pract 2006 July;(7)3:012-021.

scholarly journals Influence of Battery Level of a Cordless LED Unit on the Properties of a Nanofilled Composite Resin

2016 ◽  
Vol 41 (4) ◽  
pp. 409-416 ◽  
Author(s):  
AG Pereira ◽  
LHA Raposo ◽  
DNR Teixeira ◽  
RCQ Gonzaga ◽  
IO Cardoso ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Light Intensity ◽  
Composite Resin ◽  
Light Emitting Diode ◽  
Pearson Correlation ◽  
Composite Resins ◽  
Degree Of Conversion ◽  
Battery Voltage ◽  
Significant Difference ◽  
Diametral Tensile Strength

SUMMARY The properties of composite resins can be influenced by light activation, depending primarily on the performance of the curing unit. The aim of this study was to evaluate how different battery levels of a cordless light-emitting diode (LED) unit influence the properties of a nanofilled composite resin. First, the battery voltage and light intensity of the cordless LED unit were individually checked for all light-curing cycles. Then, composite resin discs were prepared and light-cured at different battery levels: high level (HL, 100%), medium level (ML, 50%), and low level (LL, 10%). The degree of conversion, diametral tensile strength, sorption, and solubility of the specimens were tested. Data were checked for homoscedasticity and submitted to one-way analysis of variance followed by Tukey honestly significant difference and Pearson correlation tests (p&lt;0.05). The battery voltage and light intensity varied significantly among the groups (p&lt;0.001). The LL group presented a lower degree of conversion than the HL and ML groups (p&lt;0.001), which shower similar results (p=0.182). Lower diametral tensile strength was also verified for the LL group when compared with the HL and ML groups (p&lt;0.001), which presented no difference (p=0.052). Positive correlation was observed between the light intensity and the parameters studied, with the exception of sorption and solubility (p&lt;0.001). The ML and LL groups showed higher sorption than the HL group (p &lt;0.001), but no difference was verified between the first two groups (p=0.535). No significant differences were found for solubility between the ML and LL groups (p=0.104), but the HL group presented lower values (p&lt;0.001). The different battery levels of the cordless LED curing unit influenced all the properties of the nanofilled composite resin evaluated.

scholarly journals Wear Resistance of Bulk-fill Composite Resin Restorative Materials Polymerized under different Curing Intensities

2017 ◽  
Vol 18 (1) ◽  
pp. 39-43
Author(s):  
Fahad Alkhudhairy
Keyword(s):  
Wear Resistance ◽  
Light Intensity ◽  
High Intensity ◽  
Composite Resin ◽  
Surface Loss ◽  
Low Intensity ◽  
Significant Difference ◽  
Restorative Materials ◽  
Light Curing ◽  
Curing Light

ABSTRACT Introduction The aim of this study was to assess the wear resistance of four bulk-fill composite resin restorative materials cured using high- and low-intensity lights. Materials and methods Twenty-four samples were prepared from each composite resin material (Tetric N-Ceram, SonicFill, Smart Dentin Replacement, Filtek Bulk-Fill) resulting in a total of 96 samples; they were placed into a mold in a single increment. All of the 96 samples were cured using the Bluephase N light curing unit for 20 seconds. Half of the total specimens (n = 48) were light cured using high-intensity output (1,200 mW/cm2), while the remaining half (n = 48) were light cured using low-intensity output (650 mW/cm2). Wear was analyzed by a three-dimensional (3D) noncontact optical profilometer (Contour GT-I, Bruker, Germany). Mean and standard deviation (SD) of surface loss (depth) after 120,000 cycles for each test material was calculated and analyzed using one-way analysis of variance (ANOVA) with a significance level at p < 0.05. Results The least mean surface loss was observed for SonicFill (186.52 µm) cured using low-intensity light. No significant difference in the mean surface loss was observed when comparing the four tested materials with each other without taking the curing light intensity into consideration (p = 0.352). A significant difference in the mean surface loss was observed between SonicFill cured using high-intensity light compared with that cured using low-intensity light (p < 0.001). Conclusion A higher curing light intensity (1,200 mW/cm2) had no positive influence on the wear resistance of the four bulk-fill composite resin restorative materials tested compared with lower curing light intensity (650 mW/cm2). Furthermore, SonicFill cured using low-intensity light was the most wearresistant material tested, whereas Tetric N-Ceram cured using high-intensity light was the least wear resistant. Clinical significance The wear resistance was better with the newly introduced bulk-fill composite resins under low-intensity light curing. How to cite this article Alkhudhairy F. Wear Resistance of Bulk-fill Composite Resin Restorative Materials Polymerized under different Curing Intensities. J Contemp Dent Pract 2017;18(1):39-43.

scholarly journals Experimental Study of the Classical Music and Light Intensity Effect on the Heart Rate of the Readers (A Case Study in Industrial Engineering Library, Diponegoro University)

2020 ◽  
Vol 19 (2) ◽  
pp. 108-116
Author(s):  
Heru Prastawa ◽  
Novie Susanto ◽  
Manik Mahachandra
Keyword(s):  
Heart Rate ◽  
Light Intensity ◽  
Classical Music ◽  
Industrial Engineering ◽  
National Standard ◽  
Physical Aspect ◽  
Environment Design ◽  
Lighting Condition ◽  
Intensity Effect ◽  
The Right

This paper aims at determining the effect of music and light intensity on heart rate and perceptions of visitors in Industrial Engineering Library, analyzing the performance of users in various treatment conditions and by doing so, providing recommendations for the right combination of treatments to increase concentration and increase the level of relaxation. It proves a better performance of the students when they work in better physical environment design, especially in the library. Based on preliminary studies, it is indicated that the Industrial Engineering Library (IEL) needs re-engineering of the light and sound condition. The library room does not inline with the Head of National Library of Indonesia's rules, number 13 of 2017, about the national standard of college libraries for lighting condition. Besides, about 90.2% of students feel the classical music increases comfort and concentration in reading activities. The research data was collected by recording 24 respondents' heart rate and processed by experimental design using SPSS software. The result provides recommendations from the human physical aspect by selecting the treatment to achieve the highest performance. An additional questionnaire with a Likert scale was disseminated to measure the respondents' perceptions. The results showed that the interaction of 200-600 lux lighting and classical music variables was the best treatment to achieve the highest performance.

Light intensity effect on the mechanisms of tumor damage photosensitized by a substituted Zn(II)-naphthalocyanine

2001 ◽  
Vol 05 (11) ◽  
pp. 798-802 ◽  
Author(s):  
M. SHOPOVA ◽  
M. PEEVA ◽  
N. STOICHKOVA ◽  
G. JORI ◽  
D. WÖHRLE ◽  
...  
Keyword(s):  
Photodynamic Therapy ◽  
Light Intensity ◽  
Photochemical Reaction ◽  
Optimal Conditions ◽  
Lewis Lung ◽  
Intensity Effect ◽  
Photo Oxidation ◽  
Cell Culture Systems ◽  
Tumor Reduction

Cytotoxicity induced by photodynamic therapy (PDT) is connected with the phenomena of photo-oxidation. Generation of singlet oxygen and free radicals (superoxide or hydroxide) is accepted as a mechanism for the photo-oxidation action of PDT. Very little is however known about the validity of metabolitic and biochemical events observed in cell culture systems to in vivo tumor shrinkage following PDT. In the present work using the well-studied tetrabenzamido-substituted zinc (II)-naphthalocyanine ( ZnNc ) including towards pigmented melanoma, we accessed its efficacy for apoptotic processes during PDT of Lewis lung carcinoma (LLC) in mice in dependence on light intensity. Early photodynamic therapy responses were examined at 1, 3, 6, 10 and 24 h after coherent 774 nm illumination of the tumors applied 24 h after intraperitoneal (i.p.) injection of dipalmitoylphosphatidylcholine (DPPC)-liposome-incorporated 0.5 mg kg-1 b.w. ZnNc . Fluence rates of 260, 380 and 500 mW cm-2 at a fluence of 360 J cm-2 were used. Macroscopic observations showed that tumor reduction (and its eventual elimination) depends on optimal conditions for the occurring of photochemical reaction during PDT. At the same time, electron microscopy (EM) assays demonstrated strongly expressed dependence of apoptotic processes on the applied light intensities. Features of apoptotic processes were most clearly expressed at the highest used fluence rate.

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